On 1960, President Diosdado Macapagal signed a bill creating the municipality of Valenzuela independent from Bulacan. However, on 1963, the bill was reverted, making the northern Polo under Bulacan again, while the southern Valenzuela town became an independent municipality. The creation of Metro Manila Commission and National Capital Region during Marcos'
administration led to unification of Polo and Valenzuela into a
municipality of Valenzuela in 1975. Valenzuela finally attained cityhood
status on February 14, 1998.

Spanish colonization

The history of Valenzuela is incomplete unless the history of its mother province, Bulacan, is included. For hundreds of years, present-day Valenzuela, Obando and Novaliches (now in Quezon City) were parts of Bulacan. Therefore, the history of Bulacan before 1623 was also the history of Valenzuela.

Province of Bulacan

When Spanish conquistadores reached Luzon island and established a settlement in Manila,[7] they found Bulacan as a strong united community ruled by the Rajah and his princes. Until today, the etymology of Bulacan is unclear, although many historians believe that the word bulacan came from any of the following:

1. The vast area of the region was entirely covered by green
pastures, mountains, and forests. It was also full of fruit trees,
vegetables, and flower orchards. The natives there called such a place bulak-lakan, meaning flower farm in Tagalog. It was Hispanized to bulakan, and finally, to bulacan.
2. Taking the Tagalog root word of bulacan, bulac, which in modern orthography becomes bulak or cotton. The region is also plenty of cotton trees in the north, and in fact, it is a major industry there.

Early Hispanic history of the region

The area encompassed by the present-day Valenzuela City, Novaliches, and Obando municipality and portions of land in southern Caloocan City were formerly known during Spanish period as Polo. The region, is significantly bounded by the Tullahan River on the south and streams of branching Río Grande de Pampanga on some areas.

Legazpi formally established settlement on Maynila on June 24, 1571.[8] According to Father Martinez de Zuñiga, a Spanish missionary of Augustinian order, Maynila was a vast region enclosed by the towns of Polo, Tambobong (now Malabon City), and mountains of San Mateo in Morong. The region of Valenzuela, was formally merged under the rule of Bulacan town of Catanghalan.[8]

On 1587, the Tagalog cabeza de barangay of Catanghalan Tassi Bassi joined the Tondo chieftain Magat Salamat's planned insurrection against Spanish colonization of Maynila.[10] The rebellion was composed of kin-related noblemen or maharlikas
of Maynila including Juan Banal, another Tondo chief and Salamat’s
brother-in-law; Gerónimo Basi and Gabriel Tuambacar, brothers of Agustín
de Legazpi; Pedro Balinguit, the chief of Pandacan; Felipe Salonga, the chief of Polo; Dionisio Capolo (Kapulong), the chief of Candaba and brother of Felipe Salonga; Juan Basi, the chief of Taguig;
Felipe Salalila, the chief of Misil; Agustin Manuguit, son of Felipe
Salalila; Luis Amanicaloa, another chief of Tondo; Felipe Amarlangagui,
the chief of Caranglan; Omaghicon, the chief of Navotas and Pitongatan (Pitong Gatang), another chief of Tondo. In Philippine history, this was notably known as Tondo Conspiracy of the Maharlikas,
a plot of series of "revolution" against Spain that included several
native noblemen. The planned revolution was never happened because whistleblowers revealed the nature of it to Spanish authorities.[11]

When Manila became an archdiocese on August 14, 1595 based upon Pope Gregory XIII's Papal order, regular friars that had already established permanent church in Catanghalan decided that the attached sitio of Polo be divided to cater spiritual needs of an increasing population all over.[12] Thus, on 1623, upon order of Governor-General Alonso Fajardo de Entenza,
sitio Polo became independent from Catanghalan although the two was
still under the alcaldía (Spanish title for local government during that
time) of Bulacan.

Establishment of the town

Prior to the elevation of Manila
as an archdiocese on 1595, regular friars staying on the town of
Catanghalan asked for an appeal from Governor-General Entenza to have
another separate town from former. Through successive efforts of Fray
Juan Taranco and Don Juan Monsód, sitio Polo was successfully separated from Catanghalan in 1623, but still under jurisdiction of the alcaldía de Bulacán. Thus, the first cabeza de barangay of the new town of Polo was Monsód and Taranco operated the present San Diego de Alcalá parish on a small tavern.[13]

It was in the year 1627 when the construction of the Parochial church dedicated to San Diego de Alcala
started. Finally, in 1629, the church was fully constructed. Its
fabrication was supervised by Fr. José Valencia aided by Capitan Juan
Tibay. The church was fully repaired and remodeled under the direction
of Fr. Vicente in 1852. A great change took place in the appearance of
the church, that according to the missionaries it was one of the best
ever built in the archipelago, and became the envy among other towns.
Again, the church after its repair was dedicated to another patron, the "Nuestra Senora de la Inmaculada Concepcion".
Still, another dedication was made and that was to San Roque. The
convent was well built and comfortable. The pride of its artistry lies
on the fact that the people of the town had done so much to its
perfection. Besides the convent, a descent "casa tribunal" with a
rectangular prison cell was built, and a school house also fabricated of
stones was erected.

During 1635, the Sangleys at Parian
in Manila and in the neighboring towns staged an insurrection against
the Spanish government. It was during one of these rebellions that the
church bells brought by the Spanish Missionaries to the town which was
made of bronze, and whose intonations were second only to that of the
bell of St. Peter's Basilica in Rome,
was stolen by the Chinese. Since it was so huge, the looters had to
break it into small pieces in order to remove it from the belfry.

Philippine Revolution, American occupation and World War II

The Americans established the military rule and Dr. Pío Valenzuela was appointed first president of the town on September 6, 1899. He resigned on February 1902.

Rufino Valenzuela became the first elected president of the Town in 1904.

The entrance of the Japanese
in Polo was without any resistance. The people during the Japanese time
enjoyed prosperity for Polo became a market town. There were more signs
of cooperation and social contact among the inhabitants but on the
contrary, fear of reprisals from the Japanese predominated. The town
also became a place of terror. There were too many murders committed.
The place became a habitat of Makapilis, and spies who troubled the
peaceful civilians. The sudden appearance of the Japanese added terror
to the place.

The reign of terror climaxed on December 10, 1944. It was a day of mourning for the people of Polo and Obando
for it was the day when the Japanese massacred more than a hundred
males in both towns. At about 1:00am on this day up to the setting of
the sun, cries could be heard from the municipal building when males who
were screeded by the "Magic Eye" inside the church were being tortured
to death. (This could be the reason why the old church was not anymore
restored, and be neglected to ruins, thus building a new edifice beside
the old one.) Mayor Ponciano met the same fate. He died a cruel death on
this day with the municipal officials.

When liberation came, the town was partly burned by the approaching the military forces of the Filipinos and Americans who threw flame throwers and shelled the big houses in the town, not exempting the more than 300 years old church of San Diego.

The historical old bridge was destroyed by the Japanese, thus
separating Polo in two parts, the Northern and the Southern Parts. The
northern part was at once liberated by joint Filipino and American
troops while the southern part, which includes the Poblacion was still
under the Japanese banner. The Japanese abandoned the town on February
11, 1945 when the combined American and Filipino troops were able to cross the river and took the town.

Polo, Bulacan to Valenzuela City

On July 21, 1960, President Diosdado Macapagal
signed Executive Order No. 401, which led to the creation of the
separate municipalities of Valenzuela and Polo, in honor of Dr. Pío Valenzuela, a significant personality in Philippine history
who was born here. The new town of Polo comprised the barangays on the
northern part namely Poblacion, Palasan, Arkong Bato, Pariancillo Villa,
Balangkas, Mabolo, Coloong, Malanday, Bisig, Tagalag, Rincon, Pasolo, Punturin, Bignay
and Dalandanan. The new town of Valenzuela comprised the southern
barangays: Karuhatan, Marulas, Malinta, Ugong, Mapulang Lupa, Canumay,
Maysan, Paso de Blas, Bagbaguin and Torres Bugallon (now Gen. T. de
Leon).After three years of administrating the two towns, however, the
local government and their respective constituents realized that a
division of Polo and Valenzuela was ill advised and only resulted in
underdevelopment instead of progress. Thus, on September 11, 1963,
another law, Executive Order No. 46 was signed by then President
Diosdado Macapagal; this declared the re-unification of the towns of
Polo and Valenzuela, which led to the adoption of the name "Valenzuela"
in respect to and to perpetuate the legacy of the great patriot, Dr. Pío Valenzuela.

Because of the rapid growth of the National Capital Region
in terms of population, as well as social and economic requirements in
the early seventies, and the municipality's proximity to the area,
During the Marcos administration, Valenzuela was taken from the province of Bulacan and was included in the created MMDA (Metro Manila Development Authority) and the NCR
(National Capital Region). Presidential Decree Number 824 was issued on
November 7, 1975, creating the Metropolitan Manila Commission and
separating the Municipality of Valenzuela from the Province of Bulacan.

As part of the National Capital Region,
the social and political upheavals of the seventies and early eighties
did not dampen the pulsating economy of the municipality. It was, in
fact, a golden age in the history and culture of Valenzuela when
businesses and industries in the municipality grew rapidly.

The passage of the Local Government Code in 1991 unlocked and
marshaled the repressed energies of local communities. The Local
Government Code provides genuine and meaningful autonomy to enable local
governments to attain their fullest development as self-reliant
communities. It was during this time that Valenzuela began charting its
own destiny and moved the local economy in the direction it chose.

And 23 years after its separation from Bulacan and 375 years after its founding, On February 14, 1998, then President Fidel Ramos signed Republic Act No. 8526, converting the Municipality of Valenzuela under the administration of Mayor Bobbit Carlos into a highly urbanized city, making Valenzuela the 12th city in Metro Manila and the 83rd in the Philippines.[14